Diabetes and obesity have reached epidemic proportions in the U.S. with rates consistently higher among Hispanic as compared to non-Hispanic whites. Among Hispanic women diagnosed with gestational diabetes mellitus (GDM), 50% will go on to develop type 2 diabetes within 5 years of the index pregnancy. Although randomized controlled trials among adults with impaired glucose tolerance have shown that diet and physical activity reduce the risk of type 2 diabetes, such programs have not been tested in high risk postpartum women. The overall goal of this randomized controlled trial is to test the efficacy of a culturally and linguistically modified, individually-tailored lifestyle intervention o reduce risk factors for type 2 diabetes and cardiovascular disease among postpartum Hispanic women with a history of abnormal glucose tolerance during pregnancy. Specific aims are to evaluate the impact of the intervention on 1) postpartum weight loss, 2) biomarkers associated with insulin resistance (i.e., glucose, insulin, HbA1c, leptin, TNF-, HOMA, AUCgluc, adiponectin), 3) other cardiovascular risk factors (i.e., blood lipids, blood pressure, CRP, fetuin A, albumin-to-creatinine ratio), and 4) the adoption and maintenance of postpartum behaviors associated with weight loss and prevention of diabetes risk (i.e., physical activity, diet). Eligibe Hispanic women will be recruited after routine GDM screening and randomly assigned to a Lifestyle Intervention (n=150) or a Comparison Health and Wellness (control) intervention (n=150). The intervention will be based on our efficacious exercise and dietary interventions for Hispanics (R01NR011295; WIC Common Pathways). Multimodal contacts (i.e., in-person, telephone counseling, and mailed print-based materials) will be used to deliver the intervention from randomization (29 wks gestation) to 12 months postpartum. Targets of the intervention are to achieve Institute of Medicine Guidelines for postpartum weight loss; American College of Obstetrician and Gynecologist guidelines for physical activity; and American Diabetes Association guidelines for diet. The intervention draws from Social Cognitive Theory and the Transtheoretical Model and addresses the specific social, cultural, economic, and physical environmental challenges faced by underserved Hispanic women. Measures of adherence will include accelerometers and dietary recalls. PUBLIC HEALTH RELEVANCE: Hispanic women are the fastest growing minority group in the U.S. and have the highest rates of sedentary behavior as well as postpartum diabetes after a diagnosis of gestational diabetes. This randomized controlled trial of a culturally and linguistically modified, individually tailored lifestyle intervention among postpartum Hispanic women seeks to reduce risk factors for type 2 diabetes and cardiovascular disease using a high-reach, low-cost strategy, which has great potential for adoption on a larger scale and thus high potential for reducing existing health disparities in the U.S.